support Command command

database/command.go

@@ -0,0 +1,171 @@
+package database
+
+import (
+	"github.com/hdt3213/godis/interface/redis"
+	"github.com/hdt3213/godis/redis/protocol"
+	"strings"
+)
+
+func init() {
+
+}
+
+var commandTable = make(map[string]*godisCommand)
+
+const (
+	Write         = "write"
+	Readonly      = "readonly"
+	Denyoom       = "denyoom"
+	Admin         = "admin"
+	Pubsub        = "pubsub"
+	Noscript      = "noscript"
+	Random        = "random"
+	SortForScript = "sortforscript"
+	Loading       = "loading"
+	Stale         = "stale"
+	SkipMonitor   = "skip_monitor"
+	Asking        = "asking"
+	Fast          = "fast"
+	Movablekeys   = "movablekeys"
+)
+
+type godisCommand struct {
+	name       string
+	arity      int
+	signs      []string
+	firstKey   int
+	lastKey    int
+	stepNumber int
+	prepare    PreFunc
+}
+
+func RegisterGodisCommand(name string, arity int, signs []string, firstKey int, lastKey int, stepNumber int, prepare PreFunc) {
+	name = strings.ToLower(name)
+	commandTable[name] = &godisCommand{
+		name:       name,
+		arity:      arity,
+		signs:      signs,
+		firstKey:   firstKey,
+		lastKey:    lastKey,
+		stepNumber: stepNumber,
+		prepare:    prepare,
+	}
+}
+
+func execCommand(args [][]byte) redis.Reply {
+	n := len(args)
+	if n > 1 {
+		subCommand := strings.ToUpper(string(args[1]))
+		if subCommand == "INFO" {
+			return getCommands(args[2:])
+		} else if subCommand == "COUNT" {
+			return protocol.MakeIntReply(int64(len(commandTable)))
+		} else if subCommand == "GETKEYS" {
+			if n < 2 {
+				return protocol.MakeErrReply("Unknown subcommand or wrong number of arguments for '" + subCommand + "'")
+			}
+			return getKeys(args[2:])
+		} else {
+			return protocol.MakeErrReply("Unknow subcomand or wrong number of arguments for '" + subCommand + "'")
+		}
+	} else {
+		return getAllGodisCommandReply()
+	}
+}
+
+func getKeys(args [][]byte) redis.Reply {
+	key := string(args[0])
+	command, ok := commandTable[key]
+	if !ok {
+		return protocol.MakeErrReply("Invalid command specified")
+	}
+	arity := command.arity
+	if arity > 0 {
+		if len(args) != arity {
+			return protocol.MakeErrReply("Invalid number of arguments specified for command")
+		}
+	} else {
+		if len(args) < -arity {
+			return protocol.MakeErrReply("Invalid number of arguments specified for command")
+		}
+	}
+
+	prepare := command.prepare
+	if prepare == nil {
+		return protocol.MakeErrReply("The command has no key arguments")
+	}
+	writeKeys, readKeys := prepare(args[1:])
+
+	keys := append(writeKeys, readKeys...)
+	replies := make([]redis.Reply, len(keys))
+	for i, key := range keys {
+		replies[i] = protocol.MakeBulkReply([]byte(key))
+	}
+	return protocol.MakeMultiRawReply(replies)
+}
+
+func getCommands(args [][]byte) redis.Reply {
+	replies := make([]redis.Reply, len(args))
+
+	for i, v := range args {
+		reply, ok := commandTable[string(v)]
+		if ok {
+			replies[i] = reply.ToReply()
+		} else {
+			replies[i] = protocol.MakeNullBulkReply()
+		}
+	}
+
+	return protocol.MakeMultiRawReply(replies)
+}
+
+func getAllGodisCommandReply() redis.Reply {
+	replies := make([]redis.Reply, len(commandTable))
+	i := 0
+	for _, v := range commandTable {
+		replies[i] = v.ToReply()
+		i++
+	}
+	return protocol.MakeMultiRawReply(replies)
+}
+
+func (g *godisCommand) ToReply() redis.Reply {
+	args := make([]redis.Reply, 6)
+	args[0] = protocol.MakeBulkReply([]byte(g.name))
+	args[1] = protocol.MakeIntReply(int64(g.arity))
+	signs := make([]redis.Reply, len(g.signs))
+	for i, v := range g.signs {
+		signs[i] = protocol.MakeStatusReply(v)
+	}
+	args[2] = protocol.MakeMultiRawReply(signs)
+	args[3] = protocol.MakeIntReply(int64(g.firstKey))
+	args[4] = protocol.MakeIntReply(int64(g.lastKey))
+	args[5] = protocol.MakeIntReply(int64(g.stepNumber))
+
+	return protocol.MakeMultiRawReply(args)
+}
+
+func init() {
+	RegisterGodisCommand("Command", 0, []string{Random, Loading, Stale}, 0, 0, 0, nil)
+
+	RegisterGodisCommand("Keys", 2, []string{Readonly, SortForScript}, 0, 0, 0, nil)
+	RegisterGodisCommand("Auth", 2, []string{Noscript, Loading, Stale, SkipMonitor, Fast}, 0, 0, 0, nil)
+	RegisterGodisCommand("Info", -1, []string{Random, Loading, Stale}, 0, 0, 0, nil)
+	RegisterGodisCommand("Slaveof", 3, []string{Admin, Noscript, Stale}, 0, 0, 0, nil)
+	RegisterGodisCommand("Subscribe", -2, []string{Pubsub, Noscript, Loading, Stale}, 0, 0, 0, nil)
+	RegisterGodisCommand("Publish", 3, []string{Pubsub, Noscript, Loading, Fast}, 0, 0, 0, nil)
+	RegisterGodisCommand("FlushAll", -1, []string{Write}, 0, 0, 0, nil)
+	RegisterGodisCommand("FlushDb", -1, []string{Write}, 0, 0, 0, nil)
+	RegisterGodisCommand("Save", 1, []string{Admin, Noscript}, 0, 0, 0, nil)
+	RegisterGodisCommand("BgSave", 1, []string{Admin, Noscript}, 0, 0, 0, nil)
+	RegisterGodisCommand("Select", 2, []string{Loading, Fast}, 0, 0, 0, nil)
+	RegisterGodisCommand("Replconf", -1, []string{Admin, Noscript, Loading, Stale}, 0, 0, 0, nil)
+	RegisterGodisCommand("Replconf", 3, []string{Readonly, Admin, Noscript}, 0, 0, 0, nil)
+
+	// transaction command
+	RegisterGodisCommand("Multi", 1, []string{Noscript, Fast}, 0, 0, 0, nil)
+	RegisterGodisCommand("Discard", 1, []string{Noscript, Fast}, 0, 0, 0, nil)
+	RegisterGodisCommand("Exec", 1, []string{Noscript, SkipMonitor}, 0, 0, 0, nil)
+	RegisterGodisCommand("Watch", 1, []string{Noscript, Fast}, 1, -1, 1, readAllKeys)
+
+}